Question

По горизонтальній ділянці дороги з постійною швидкістю 1 м/с тягнуть сталевий брусок. На скільки градусів нагріється брусок протягом 10 хвилин внаслідок тертя о дорогу? Коефіцієнт тертя між дорогою та бруском 0,6, в оточуюче середовище уходить 50 % тепла, отриманого від тертя. Питома теплоємність сталі 500 Дж/(кг×0С

Answer 1

Ню(КПД=0,5)*А=Q     A=FS=FVt=мю(коэффициент трения)mgVt      
 F=мю(коэффициент трения)mg
Q=Cc*m*дельта t         ню* мю*m*g*V*t=Cc*m*дельта t 
 дельта t =ню* мю(коэффициент трения)mgVt / Cc*m=
=  мю(коэффициент трения)gVt / Cc=0,5*0,6*10*1*600/500= 3,6[градуса]  

Answer 2

To calculate the temperature increase of the steel block due to friction with the road, we can use the formula:

Q = m * c * ΔT

Where: - Q is the heat generated by friction - m is the mass of the steel block - c is the specific heat capacity of steel - ΔT is the change in temperature

Given: - The steel block is being pulled with a constant speed of 1 m/s - The coefficient of friction between the road and the block is 0.6 - The surrounding environment absorbs 50% of the heat generated by friction - The specific heat capacity of steel is 500 J/(kg·°C) - The time duration is 10 minutes (600 seconds)

Let's calculate the temperature increase step by step:

Step 1: Calculate the heat generated by friction (Q)

The heat generated by friction can be calculated using the formula:

Q = F * d

Where: - F is the frictional force - d is the distance traveled

Since the block is being pulled with a constant speed, the frictional force can be calculated using:

F = μ * N

Where: - μ is the coefficient of friction - N is the normal force (equal to the weight of the block)

Since the block is being pulled horizontally, the normal force is equal to the weight of the block:

N = m * g

Where: - m is the mass of the block - g is the acceleration due to gravity (approximately 9.8 m/s²)

Therefore, the heat generated by friction can be calculated as:

Q = μ * m * g * d

Step 2: Calculate the change in temperature (ΔT)

The change in temperature can be calculated using the formula:

ΔT = Q / (m * c)

Where: - Q is the heat generated by friction - m is the mass of the block - c is the specific heat capacity of steel

Step 3: Calculate the temperature increase

The temperature increase can be calculated by multiplying the change in temperature by the percentage of heat absorbed by the surrounding environment:

Temperature increase = ΔT * (1 - 0.5)

Now let's substitute the given values and calculate the temperature increase.

According to the given information, the coefficient of friction (μ) is 0.6, the specific heat capacity of steel (c) is 500 J/(kg·°C), and the time duration is 10 minutes (600 seconds).

Using these values, we can calculate the temperature increase.